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Biomedical subjects

B Losev

Publications and source records attributed to B Losev.

6 recordsLinked to original sources
PubMed2001

[Interrelations between cells of the nervous and immune systems in vitro].

The collaborative character of the immune response requires direct cell- to cell or humoral contacts between the lymphocytes and the cells of mononuclear phagocyte system. The proposed model of direct interrelationship between the cells of the CNS and the immune system throws much light on the morphology of the lymphocyte entry and its recruitment into parenchyma during pathology. The structure, distribution and membrane morphology of the formed in situ rosette-like clusters (containing microglia, as CNS type of mononuclear phagocytes, and syngeneic lymphocytes) was investigated by light and scanning electron microscopy (SEM). The results were discussed in relation with the strong expression of a number of immune capacities from the ubiquitiously situated in the CNS microglia and the pivotal role of the lymphocytes and microglia in pairs with a close contact to each other in the brain immune processing.

Animals↗
PubMed1987

[Isolation of conjugated sera for the immunofluorescence demonstration of swine parvovirus].

High-titer, specific serum against porcine parvovirus was obtained via hyperimmunization of rabbits, with the use of a Bulgarian isolate that had been partially purified after a known, modified technique. A specific, high-titer conjugate was produced for the immunofluorescence diagnosis of porcine parvoviruses. The microscopic observation of the lamellae of cell cultures, treated with the conjugate, revealed the presence of a specific, typically granulated perinuclear (mostly unilaterally) and, in some cases nuclear fluorescence--at negative reaction in the control preparations. Immunofluorescent light was also established in cell cultures infected with the virus at highest dilution. It showed that immunofluorescence microscopy could be employed to demonstrate even the lowest amounts of the virus.

Animals↗
PubMed1978

Morphological and physical characteristics of an antigen associated with viral hepatitis type A (Botevgrad antigen).

Immune electron microscopy (IEM) was employed in studying faecal samples of viral hepatitis type A patients and their contacts, in whom the presence of an antigen, differing from the HBsAg, designated as Botevgrad antigen (BA) was proved by the CFT. Particles 25--28 nm in diameter, aggregated by sera positive for the anti-HAAg were established in the faecal samples. The buoyant density of these particles in CsCl was found to be 1.40 g/ml. Particles of the same buoyant density were established also in sera positive for BA which were aggregated in large masses with antiserum against BA obtained from rabbits. The associations between BA and HAAg are discussed.

Animals↗
PubMed1975

[Serologic studies in viral hepatitis].

Comparative studies of sera from 710 patients with viral hepatitis and contacts were made during the 1958-1973 period for hepatitis antigens (Au antigen and the Botevgrad antigen). The percentage of virus hepatitis in patients positive for the Au and the Botevgrad antigens varied in different years. The percentage of those positive for the Au antigen ranged from 50 in 1958 to 8.8 in 1970-1971, while for the Botevgrad antigen--it ranged from 32.6 in 1962-1963 to 6.1 in 1966. In case of contacts, mostly in the 7-14 age group the sera positive for the Au antigen were found in a low percentage (2.09 percent) of cases; as to the Botevgrad antigen, 20 persons were found positive during various epidemics (55 percent). Simultaneous presence of both antigens was found in 4 of the 710 patients with virus hepatitis (0.56 percent), and in 2 of 431 contacts (0.46 percent).

Antigens, Viral↗
PubMedDate not supplied

[Development of cellular immunity in patients with viral hepatitis].

The development of cell-mediated immunity (CMI) to the surface antigen of hepatitis B virus (HBSAg) and Botevgrad antigen (BA) was traced in 50 hepatitis patients. Migration inhibition test (MIT) was performed with purified HBSg and AB. Blood samples from every hepatitis patient were obtained at the beginning of the icteric phase, 10 days later and during convalescence. There was correlation between the two types of viral hepatitis and the type of cellular immune response. The development of CMI is associated with disappearance of HBSAg from the serum of hepatitis patients. CMI to HBSAg develops within 9-12 days after the onset of icterus and to BA during the first two days of icterus. There is a relationship between the persistence of HBSAg and CMI.

Bilirubin↗